If you're tired of touching that touchscreen, try hitting your phone and making some noise.

Researchers in South Korea have developed a sound-based method of controlling smartphones, and connected appliances, by tapping them.

Graduate students from Seoul National University of Science and Technology are demonstrating an Android app called Sound Tap at the 2015 Computer-Human Interaction Conference (CHI) in Seoul this week.

Sound Tap can be used to control a smartphone by tapping its rear surface with a finger once or twice, or by lightly striking the phone itself against various surfaces in the environment. Since the taps create unique frequencies, they can be used to trigger different functions on the phone, such as calling up browsers, photo galleries or music players.

For instance, tapping the phone on a steering wheel while driving could call up the phone's map or navigation apps. Tapping the back of the phone with a finger when going to bed could turn off connected household lights, or activate an alarm clock in the phone.

Beer-powered train times

Another scenario presented by the researchers involves a user drinking in a bar. Tapping the phone on a bottle of beer can call up the schedule for the last train on the local subway.

The technology uses microphones and motion sensors and can be used in any smartphone without the need for extra hardware, the researchers said.

Users have to briefly train a machine-learning algorithm by tapping the phone a number of times, and then associating that sound with a function.

"We wanted to create a system that would let you easily control a smartphone using one hand only," said Park Min-ji, a masters student in IT design at Seoul National University of Science and Technology.

Park and colleagues want to improve the app so that it performs better in very noisy environments.

Interest from Samsung

Samsung Electronics provided software support for the project through an industry-university program, and has shown interest in developing Sound Tap, according to Park.

The know-how in the app might also work with Samsung Flow, a technology that lets users shift through different mobile devices while performing an activity, for instance she said.

Using sound as an input method for smartphones has also been explored by Disney Research and Carnegie Mellon University, which are demoing ultrasound-based plastic knobs for smartphones at CHI 2015 this week.